Yes, I should have mentioned the accuracy-consistency-precision issue. I don't know if the item for sale is calibratable in software. That would be a nice touch. In the end we don't know how the iCelsius sensor is implemented, what sensor (and specs) it uses, or how good the software is. But they don't claim better accuracy than I mentioned in my earlier post. I'd make my own calibrated version for the same or less money.
With many devices, like the LM34/35/36/37, the grading varies, with the more accurate versions selling for over US$8 and the lower accuracy versions for US$2. I doubt that the iCelsius uses a higher spec sensor at its price. However with these devices a simple offset variable will align them correctly to the scale, and then they are all spec'd to be linear within ±0.5°F across their full scales, from -50° to +300°F in the case of the LM34. Again, I'd suspect that's not done very well, if at all, in a hardware/software package at this price point, and given the accuracy claims.
Richard and Ralph are correct on all points, including the digital thermometer being a better value.